added 31st Python tip

Author: learnbyexample

README.md

@@ -69,6 +69,7 @@ I'm addicted to reading fantasy/sci-fi books, so I have a [blog](https://learnby
 
 ## Tips
 
+* [Python tip 31: next() function](https://learnbyexample.github.io/tips/python-tip-31/)
 * [Vim tip 29: greedy quantifiers](https://learnbyexample.github.io/tips/vim-tip-29/)
 * [CLI tip 30: extract only the matching portions](https://learnbyexample.github.io/tips/cli-tip-30/)
 * [Python tip 30: zip() function](https://learnbyexample.github.io/tips/python-tip-30/)

atom.xml

@@ -5,8 +5,58 @@
 	<link href="https://learnbyexample.github.io/atom.xml" rel="self" type="application/atom+xml"/>
   <link href="https://learnbyexample.github.io"/>
 	<generator uri="https://www.getzola.org/">Zola</generator>
-	<updated>2023-07-19T00:00:00+00:00</updated>
+	<updated>2023-07-25T00:00:00+00:00</updated>
 	<id>https://learnbyexample.github.io/atom.xml</id>
+	<entry xml:lang="en">
+		<title>Python tip 31: next() function</title>
+		<published>2023-07-25T00:00:00+00:00</published>
+		<updated>2023-07-25T00:00:00+00:00</updated>
+		<link rel="alternate" href="https://learnbyexample.github.io/tips/python-tip-31/" type="text/html"/>
+		<id>https://learnbyexample.github.io/tips/python-tip-31/</id>
+		<content type="html">&lt;p&gt;The &lt;a href=&quot;https:&#x2F;&#x2F;docs.python.org&#x2F;3&#x2F;library&#x2F;functions.html#next&quot;&gt;&lt;code&gt;next()&lt;&#x2F;code&gt;&lt;&#x2F;a&gt; builtin function can be used on an iterator (but not iterables) to retrieve the next item. Once you have exhausted an iterator, trying to get another item will result in a &lt;code&gt;StopIteration&lt;&#x2F;code&gt; exception. Here&#x27;s an example:&lt;&#x2F;p&gt;
+&lt;pre data-lang=&quot;python&quot; style=&quot;background-color:#f5f5f5;color:#1f1f1f;&quot; class=&quot;language-python &quot;&gt;&lt;code class=&quot;language-python&quot; data-lang=&quot;python&quot;&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span&gt;names &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;= &lt;&#x2F;span&gt;&lt;span&gt;(m &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;for &lt;&#x2F;span&gt;&lt;span&gt;m &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;in &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;dir&lt;&#x2F;span&gt;&lt;span&gt;(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#a2a001;&quot;&gt;tuple&lt;&#x2F;span&gt;&lt;span&gt;) &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;if &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;__&amp;#39; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;not in &lt;&#x2F;span&gt;&lt;span&gt;m)
+&lt;&#x2F;span&gt;&lt;span&gt;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;next&lt;&#x2F;span&gt;&lt;span&gt;(names)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;count&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;next&lt;&#x2F;span&gt;&lt;span&gt;(names)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;index&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;next&lt;&#x2F;span&gt;&lt;span&gt;(names)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;Traceback &lt;&#x2F;span&gt;&lt;span&gt;(most recent call last):
+&lt;&#x2F;span&gt;&lt;span&gt;  File &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;quot;&amp;lt;stdin&amp;gt;&amp;quot;&lt;&#x2F;span&gt;&lt;span&gt;, line &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b3933a;&quot;&gt;1&lt;&#x2F;span&gt;&lt;span&gt;, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;in &amp;lt;&lt;&#x2F;span&gt;&lt;span&gt;module&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#a2a001;&quot;&gt;StopIteration
+&lt;&#x2F;span&gt;&lt;&#x2F;code&gt;&lt;&#x2F;pre&gt;
+&lt;p&gt;Here&#x27;s a practical example to get a random item from a &lt;code&gt;list&lt;&#x2F;code&gt; without repetition:&lt;&#x2F;p&gt;
+&lt;pre data-lang=&quot;python&quot; style=&quot;background-color:#f5f5f5;color:#1f1f1f;&quot; class=&quot;language-python &quot;&gt;&lt;code class=&quot;language-python&quot; data-lang=&quot;python&quot;&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; import &lt;&#x2F;span&gt;&lt;span&gt;random 
+&lt;&#x2F;span&gt;&lt;span&gt;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span&gt;names &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;= &lt;&#x2F;span&gt;&lt;span&gt;[&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Jo&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Ravi&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Joe&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Raj&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Jon&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;]
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span&gt;random.&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;shuffle&lt;&#x2F;span&gt;&lt;span&gt;(names)
+&lt;&#x2F;span&gt;&lt;span&gt;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span&gt;random_name &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;= &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;iter&lt;&#x2F;span&gt;&lt;span&gt;(names)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;next&lt;&#x2F;span&gt;&lt;span&gt;(random_name)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Jon&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt; &lt;&#x2F;span&gt;&lt;span style=&quot;color:#b39f04;&quot;&gt;next&lt;&#x2F;span&gt;&lt;span&gt;(random_name)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;Ravi&amp;#39;
+&lt;&#x2F;span&gt;&lt;&#x2F;code&gt;&lt;&#x2F;pre&gt;
+&lt;p&gt;You can set a default value to be returned instead of the &lt;code&gt;StopIteration&lt;&#x2F;code&gt; exception. Here&#x27;s an example:&lt;&#x2F;p&gt;
+&lt;pre data-lang=&quot;bash&quot; style=&quot;background-color:#f5f5f5;color:#1f1f1f;&quot; class=&quot;language-bash &quot;&gt;&lt;code class=&quot;language-bash&quot; data-lang=&quot;bash&quot;&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; letters &lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;= &lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;iter&lt;&#x2F;span&gt;&lt;span&gt;(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;fig&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span&gt;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; next(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;letters, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;f&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; next(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;letters, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;i&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; next(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;letters, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;g&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; next(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;letters, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#72ab00;&quot;&gt;&amp;gt;&amp;gt;&amp;gt;&lt;&#x2F;span&gt;&lt;span&gt; next(&lt;&#x2F;span&gt;&lt;span style=&quot;color:#5597d6;&quot;&gt;letters, &lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;&lt;&#x2F;span&gt;&lt;span&gt;)
+&lt;&#x2F;span&gt;&lt;span style=&quot;color:#d07711;&quot;&gt;&amp;#39;a&amp;#39;
+&lt;&#x2F;span&gt;&lt;&#x2F;code&gt;&lt;&#x2F;pre&gt;
+&lt;p&gt;&lt;strong&gt;Video demo&lt;&#x2F;strong&gt;:&lt;&#x2F;p&gt;
+&lt;p align=&quot;center&quot;&gt;&lt;iframe width=&quot;560&quot; height=&quot;315&quot; loading=&quot;lazy&quot; src=&quot;https:&#x2F;&#x2F;www.youtube.com&#x2F;embed&#x2F;CxgjN1V5vA0&quot; title=&quot;YouTube video player&quot; frameborder=&quot;0&quot; allow=&quot;accelerometer; clipboard-write; encrypted-media; gyroscope; picture-in-picture&quot; allowfullscreen&gt;&lt;&#x2F;iframe&gt;&lt;&#x2F;p&gt;
+&lt;br&gt;
+&lt;p&gt;&lt;img src=&quot;&#x2F;images&#x2F;info.svg&quot; alt=&quot;info&quot; &#x2F;&gt; See also my &lt;a href=&quot;https:&#x2F;&#x2F;github.com&#x2F;learnbyexample&#x2F;100_page_python_intro&quot;&gt;100 Page Python Intro&lt;&#x2F;a&gt; ebook.&lt;&#x2F;p&gt;
+</content>
+	</entry>
 	<entry xml:lang="en">
 		<title>Vim tip 29: greedy quantifiers</title>
 		<published>2023-07-19T00:00:00+00:00</published>

sitemap.xml

@@ -435,7 +435,7 @@
     </url>
     <url>
         <loc>https://learnbyexample.github.io/tips/</loc>
-        <lastmod>2023-07-19</lastmod>
+        <lastmod>2023-07-25</lastmod>
     </url>
     <url>
         <loc>https://learnbyexample.github.io/tips/cli-tip-1/</loc>
@@ -653,6 +653,10 @@
         <loc>https://learnbyexample.github.io/tips/python-tip-30/</loc>
         <lastmod>2023-07-04</lastmod>
     </url>
+    <url>
+        <loc>https://learnbyexample.github.io/tips/python-tip-31/</loc>
+        <lastmod>2023-07-25</lastmod>
+    </url>
     <url>
         <loc>https://learnbyexample.github.io/tips/python-tip-4/</loc>
         <lastmod>2022-06-10</lastmod>